Organic electronic devices, such as organic light-emitting devices (OLEDs), are susceptible to degradation when exposed to environmental contaminants, such as water vapor or oxygen. For example, exposure to moisture and/or oxygen can cause degradation of the light-emitting material, cause “dark spots” or pixel shrinkage, or reduce the useful lifetime of the OLED. To address this problem, OLED displays are commonly fabricated on thick, rigid glass substrates with a glass or metal cover sealed at the edges to enclose the light-emitting element. To provide further protection, it is conventional to also place a desiccant inside the sealed compartment enclosing the light-emitting element. However, this desiccant arrangement is not suitable for many types of flexible OLEDs where a flexible thin-film barrier is used to encapsulate the device. Thus, there is a need for improved means to protect electronic devices, such as OLEDs, from environmental contaminants.